The former Cardiff University lecturer, 45, attached numbers to the factors and created a happiness formula: O + (N x S) + Cpm/T + He.

When a value for being outdoors (O) is added to nature (N) multiplied by social interaction (S), added to childhood summer memories (Cpm) divided by temperature (T), and added to holiday excitement (He) then the third Friday in June comes out as the optimal day for peak happiness.

Ok, so looking at the actual formula makes it all seem pretty silly. You have to admit though, it’s about the time when the sun does start to come out more often here in the Northwest and people head out to the parks.